SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2d190de37601c2db20d7dc20ac1963054a2f2e663e0f6f61fd791fe56230043' 
  AND token = '2I4CYZZFbplTGkXX8iOcgzL+5mu7kwj6ZVCOg/xv/EY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}